The invention relates to devices and systems that deposit small quantities of fluid upon substrates in a precise manner and in arrays of desired density and consistency, and especially to cleaning such systems and other equipment in the laboratory. The invention is useful, for instance, in preventing cross-contamination when carrying out reactions, in providing accurate overlays of deposits, and, in particular, in preparing microscope slides and membranes with biological materials, for instance, microarrays for drug delivery, gene research and clinical use.
In well developed biological analytical technology, and in recently developed biochip technology, creation of dense arrays of fluorescently labeled micro-organisms and DNA assays in a two dimensional field is performed. It is desirable to place the arrays on a conventional microscope slide, or other carrier and to create many such slides simultaneously in a manufacturing process.
For biochip technology to proceed to complete fruition, as well as to improve the application of previous analytical techniques, economical instruments and systems have been needed that can, without contamination, rapidly and accurately create the dense array of objects over a large field portion of a glass microscope slide or a slide-like member that occupies an area approximately 22 mm wide and 50 mm long of a slide that is nominally 25 mmxc3x9775 mm.
In the deposition upon a microscope slide of discrete, minute quantities of a large variety of fluid materials, the volume deposited at a discrete spot typically may be from a few pico liter to a fraction of a micro liter, depending upon the application. The devices for forming such deposits are small and may have high surface energy. The biological material carried in this fluid can range from a few strands of short oligonucleotides in a water solution to a high concentration of long strands of complex proteins. The properties of these fluids vary enormously. Some are akin to water while others are far more viscous, resembling a light oil or honey. The range of fluids that may be employed also exhibits wide differences in other properties that make clean up difficult.
Such a large range of property variations in fluids of interest has caused difficulties for any single type of process to operate over a wide range to produce the desired array of deposits, to maintain such instrument clean and avoid contamination of the deposited array, the used biological material and various fluids used for deposition.
One purpose of the invention is to provide a technology deposition of very small drops of fluids, and arrays of drops, e.g. drops that form spots of less than about 375 or 300 xcexcm diameter, and in important cases, very much smaller than that, deposited at correspondingly high densities. As used in this application, the term fluid xe2x80x9cdropxe2x80x9d refers to a very small quantity of fluid or fluid including solid material, and not to any particular shape of the fluid volume. When depositing an array of drops, it is important to avoid contamination in progressing from work with one material to another as well as contamination of the source material.
The present invention relates to methods and apparatuses used for depositing a biological or other material on a receiving surface and creation of an array. The deposited array is suitable for sample acquisition, preparation microscopic analysis, reaction or other purposes. The deposited array is useful in a variety of biological applications some of which are described in U.S. Pat. Nos. 4,965,188; 5,143,854; 5,384,261; 5,856,174, which are incorporated by reference.
According one aspect, an apparatus for depositing an array of spots on a receiving surface includes a fluid source (or source means), a deposit device that includes a drop-carying surface (or deposit means), and a cleaning device (or cleaning means). The deposit device and a fluid source are cooperatively arranged to deposit a spot (usually created by a drop) on a receiving surface. The cleaning device is constructed and arranged to clean the drop-carying surface by employing a flow of cleaning fluid (or another cleaning matter such as small particles). , The apparatus may include additional optional elements discussed below and/or shown in the drawings. The cleaning device may include a fluid jet constructed and arranged to blow the cleaning fluid. The fluid jet may be constructed and arranged to blow,the cleaning fluid at least partially along a length of the deposit device toward the drop-carrying surface. The drop-carrying surface may be located at least partially within a confinement chamber.
The deposit device may have a pin-like structure with the drop-carrying surface disposed in a distal end of the pin-like structure. The drop-carrying surface may have a diameter less than 375 micron, preferably less than 300 micron, preferably between about 15 and 250 micron. The pin-like structure may include sides that intersect with an end surface that defines a rim of the drop-carrying surface.
The apparatus may include one or several fluid sources. The fluid source may include or be used with a mobile supply device, associated with the deposit device, and arranged to supply material for deposition of the array of spots. The fluid source may include or be used with a mobile local supply device arranged to move partially with the pin-like structure. The deposit device and the mobile supply device may be movable together to the cleaning device in response to a control system.
The mobile local supply device may include an annular member through which the deposit device operates by a relative motion of the drop-carrying surface, and the cleaning device may include a nozzle for directing a flow of the cleaning fluid past the annular member and the drop-carrying surface.
The apparatus may include one or several cleaning devices. The cleaning device is constructed and arranged to deliver the cleaning fluid at least partially to the mobile supply device or the mobile local supply device. The mobile local supply device includes a ring-like structure located near the drop-carrying surface. The cleaning device may be constructed and arranged to deliver the cleaning fluid at least partially to the ring-like structure and the drop-carrying surface.
The apparatus may further include a drying device constructed to discharge drying fluid. Alternatively, the drying device is included in the cleaning device and is constructed to discharge drying fluid using the fluid jet used for cleaning. The fluid jet may have various designs and may include a circular nozzle constructed to emit a conical flow of the cleaning or drying fluid achieving venturi effect, or may include an annular or other nozzle.
The apparatus may further include a reservoir for receiving the cleaning or drying fluid. A vacuum pump or another pumping device may be associated with the reservoir. The reservoir receives the cleaning or drying fluid emitted from the fluid jet. The fluid jet or nozzle may be located inside a containment chamber or outside the chamber. The pump may create a pressure differential for removing the cleaning or drying fluid emitted from the fluid jet.
The apparatus may include two or more fluid paths associated with at least two fluid reservoirs and connectable to the fluid jet. The apparatus may be associated with a control system arranged to control a flow velocity of the cleaning fluid. The apparatus may be associated with a control system arranged to select a type of the cleaning fluid. The control system may be arranged to select the type of the cleaning fluid at a source location. The cleaning fluid is selected from one of the following compressed gas, high-pressure liquid, aerosol and heated gas.
The apparatus may include four or more deposit devices and a mechanism for moving each deposit device independently toward and away from the receiving surface to deposit respective drops at respective deposit locations on the receiving surface. Alternatively, the mechanism may move the deposit devices simultaneously, relatively, toward and away from the receiving surface to deposit respective drops at respective deposit locations on the receiving surface. The deposit devices may be mounted on a common support that is driven by a common driver to deposit respective fluid drops on the receiving surface. These deposit devices may be associated with respective storage rings, wherein the storage rings are mounted on a common storage support driven by a common storage drive.
The apparatus may include a mobile fluid storage device that is movable relative to an array of deposit locations, wherein the mobile supply device is constructed and arranged to resupply the deposit device at various locations along the array. Preferably the deposit device and the mobile storage device are constructed to supply drops to the deposit device in the immediate vicinity of the deposit locations for respective drops and preferably being coupled for transverse motion relative to the array and decoupled for movement of the deposit device toward and away from the receiving surface.
According to yet another aspect, an apparatus for depositing fluid dots on a receiving surface in an array (e.g., for microscopic analysis reaction and the like) includes a deposit device and a fluid source which are cooperatively related to enable the deposit device to precisely size a drop of fluid of small diameter on a drop-carrying surface of the device, transport mechanism for positioning the device at a precisely referenced lateral position over the receiving surface and drive mechanism for moving the deposit device, relatively, in deposition motion toward and away from the surface, the apparatus adapted, by repeated action, to deposit the drops of fluid precisely in a desired array, and then to proceed to a cleaning station where the instrument is cleaned and then to a resupply station for further action with regard to other materials, free of contamination, preferably the apparatus being computer controlled.
Preferred embodiments have one or more of the following features.
A cleaning station comprises a fluid jet arranged to blow down along the length of the deposit device toward its drop-depositing end, the jet and device being within a confinement chamber thus preventing contamination.
The deposit device is a pin or pin-like structure having an end surface that carries the fluid drop, preferably the pin or pin-like structure having sides that intersect with the end surface to define a sharp peripheral drop-defining rim.
According to yet another aspect, an apparatus for depositing fluid drops on a receiving surface includes a deposit device and a fluid source which are cooperatively related to provide to a drop-carrying surface of the deposit device a precisely sized drop of fluid, and a cleaning system that effectively cleans the pin, the deposit device being a pin or pin-like structure having an end surface that serves as the drop-carrying surface, the pin or pin-like structure having sides that intersect with the end surface to define a sharp peripheral drop-defining rim.
Preferred pins or pin-like structures have an end surface that is generally flat and side surfaces that are cylindrical and smooth.
In many important cases, the fluid source is a mobile fluid storage device that is movable relative to an array of deposit locations, the fluid storage device being constructed and arranged to resupply the deposit device at various locations along the array.
According to yet another aspect, an apparatus for depositing fluid drops on a receiving surface, includes a deposit device and a fluid source which are cooperatively related to provide to the deposit device a drop of fluid, transport mechanism for positioning the deposit device over a receiving surface and drive mechanism for moving the deposit device, relatively, in deposition motion toward and away from the receiving surface, the apparatus adapted, by repeated action, to deposit the drops of fluid in a desired array, the fluid source being a mobile fluid storage device that is movable relative to the array of deposit locations, the fluid storage device being constructed and arranged to resupply the deposit device at various locations along the array, the system adapted to effectively clean the instruments between changes of fluids.
In preferred embodiments employing a mobile storage device, the deposit device and the mobile storage device are constructed to supply drops to the deposit device in the immediate vicinity of the deposit locations for respective drops, preferably the mobile fluid storage device and the deposit device being coupled for transverse motion relative to the array and decoupled for movement of the deposit device toward and away from the receiving surface.
In many cases the mobile storage devices or mobile local storage devices are constructed and arranged to be replenished from a remotely located large reservoir. In many cases a mobile storage device holds a volume of fluid having a free surface into which the deposit device is lowered and raised to obtain a fluid drop, preferably the mobile storage device being constructed to store a multiplicity of isolated fluid volumes in the wells of a multiwell plate, the apparatus constructed to obtain its fluid from a selected volume of the plate.
In other important cases a mobile local storage device defines a generally annular fluid retention surface or ring (the term xe2x80x9cannularxe2x80x9d or xe2x80x9cringxe2x80x9d being used to refer broadly to a member that has opposed, or adjacent, surfaces that can hold a mass of fluid between them by surface tension effects, accessible to a deposit device) and the deposit device is constructed to move within the annular retention surface from retracted to extended positions, in the retracted position the drop-carrying surface of the deposit device being retracted from the surface of fluid retained by the annular surface of the storage device, and in the extended position the drop-carrying surface of the deposit device being projected through and beyond the surface of the retained fluid. Advantageously, the cleaning device can cleans the pin and ring simultaneously.
According to yet another aspect, an apparatus for depositing fluid drops on a receiving surface in an array suitable for microscopic analysis, comprising a deposit device and a fluid source which are cooperatively related to provide to a drop-carrying surface of the deposit device a precisely sized drop, and a drive mechanism for moving the deposit device, relatively, in deposition motion toward and away from the receiving surface, the storage device defining a generally annular fluid retention surface, and the deposit device being constructed to move within the annular retention surface from retracted to extended positions, in the retracted position the drop-carrying surface of the deposit device being retracted from the surface of the fluid retained by the annular surface of the storage device, and in the extended position the drop-carrying surface of the deposit device being projected through and beyond the surface of the retained fluid, the relative position of the deposit device and the storage surface being adjustable so that at the cleaning station an optimal relationship for cleaning can be achieved.
In preferred embodiments, a member that defines an annular fluid retention surface is associated with a driver that moves the member relative to the deposit device to a replenishment volume in which the member is immersed to receive a supply of fluid, and to a cleaning position when the system arrives at the cleaning station.
In certain preferred embodiments the deposit device is a pin or pin-like structure e.g. having one or more of the features described above, the pin or pin-like structure being mounted within the confines of an annular fluid retention surface and arranged to move axially relative thereto.
The apparatus of any of the aspects and preferred embodiments described preferably include a control system adapted to control relative movement of the deposit device to a depositing relationship to the receiving surface and a cleaning relationship to the cleaning system.
According to yet another aspect, an apparatus for depositing an array of dots on a receiving surface, comprising a deposit device in the form of a pin or pin-like structure having an end surface capable of precisely defining a small drop of fluid, a source of fluid for the deposit device, mechanism for moving the deposit device relatively over an array of spaced apart deposit locations of a receiving surface, mechanism for repeatedly moving the deposit device, relatively toward and away from the receiving surface to deposit respective drops of fluid at selected deposit locations, a cleaning system, and a control system adapted to control relative movement of the deposit device between a resupply relationship to the source, a depositing relationship to the substrate and a cleaning relationship to the cleaning system.
In embodiments in which the deposit device is associated with a mobile supply device that travels with it, the deposit device and mobile supply device are preferably movable together to the cleaning system in response to the control system, preferably the mobile supply device being an annular member through which the deposit device operates. Preferably the cleaning system has a nozzle for directing a flow of air past the annular structure, preferably a cleaning or drying station comprising a circular nozzle is constructed to discharge a conical flow of fluid, preferably compressed air, high pressure liquid, an aerosol or heated air against a deposit device or mobile fluid source, preferably the deposit device being a pin or pin-like structure surrounded by a mobile reservoir in the form of an annular member capable of holding a supply of fluid by surface tension effects, the nozzle flows directed to dislodge retained fluid, to clean or to dry the respective parts; in some cases, preferably a circular storage device is associated with a heater, e.g., an induction heater.
Preferably, each device to be cleaned has its own cleaning chamber to which it travels, for removal of previous fluid, washing and drying in a so-called xe2x80x9cone stop shopxe2x80x9d designed to prevent contamination during cleaning.
In certain preferred embodiments of the various aspects and features described there are provided a set of at least two of the deposit devices, preferably many more, at least one fluid source for providing a drop of fluid on each deposit device, and mechanism for moving the pins together transversely over an array of spaced apart deposit locations of the receiving surface, and to a cleaning station for the respective deposit devices, preferably there being at least four of the deposit devices comprising a deposit head. Preferably the apparatus includes mechanism for repeatedly moving each deposit device independently, or mechanism for moving each deposit device simultaneously, relatively, toward and away from the supply device for resupply, the receiving surface to deposit respective drops at respective deposit locations on the receiving surface, and, optimally the cleaning station.
For simultaneous actuation, preferably two or more deposit devices are mounted on a common support, driven by a common driver to deposit respective fluid drops on the receiving surface. In cases in which each deposit device is associated with a respective storage ring, the storage rings are also mounted on a common support, driven by a common drive; preferably the spacing of the rings corresponds to the spacing of a multiwell storage plate into which the rings are immersed for resupply. In cases in which the deposit device is lowered directly into fluid and raised to obtain its drop, preferably the spacing of the deposit devices corresponds to the spacing of wells of a predetermined multiwell plate, the multiwell plate being a mobile fluid supply that is constructed to accompany the deposit device across the substrate. In the case of supply rings or direct dipping of the deposit devices, preferably the spacing corresponds to well-to-well spacing of wells of a 96, 192, 384, 864 or 1536 well plate, or a spacing of 9 mm or a submultiple of 9 mm. Likewise in this case and others, the deposit devices register with discrete cleaning stations for the individual elements, in which preferably, high speed fluid flow is directed toward the instruments being cleaned, but in a direction away from the work environment. Preferably, the high speed flow induces air flow from the work environment along the device being cleaned to create a negative pressure condition in the work environment and avoid backflow of contaminants from the containment chamber.
The apparatus of any of the foregoing is preferably constructed to mount a number of microscope slides or slide-like structures to serve as the receiving surface, and a control system is constructed and arranged to deposit drops of fluid in selected locations on the slides or slide-like structures, preferably the fluid source comprising a source of biological fluid.
Preferably, for depositing fluid drops in a dense array of mutually isolated dots, a deposit assembly is constructed to travel to a cleaning station, and comprises a fluid source for repeatedly providing a discrete drop of fluid on the tip of the deposit device, mechanism for moving the device relatively over an array of spaced apart deposit locations of a receiving surface, mechanism for repeatedly moving the device, relatively, toward and away from the receiving surfaces to deposit respective dots at respective deposit locations on the surface, preferably the fluid source being a mobile fluid storage device separate from the deposit device, which is generally movable over the array of deposit locations, the fluid storage device being constructed and arranged to resupply the deposit device at various locations with respect to the array.
In certain preferred embodiments of this aspect also, the deposit device is a slidable pin or pin-like structure constructed and arranged to dip into a volume of fluid carried by a mobile storage device, preferably the storage device being constructed to store a multiplicity of isolated fluid volumes, the apparatus constructed to move the supply device relative to the deposit device to select the fluid to be deposited, preferably the storage device being a 96 well plate or a plate having a multiple of 96 wells, and also preferably including at least one driven stage for moving a selected well of a mobile multiwell plate into registry with the deposit device under computer control for enabling motion of the deposit device to dip into and out of the preselected well to provide a drop of the selected fluid to the device.
According to yet another aspect, a deposit apparatus includes a multiplicity of deposit devices as described, mounted for motion together in response to a common actuator, preferably the deposit devices comprising deposit pins or pin-like structures adapted to enter respective cells of a cleaning station of the kind described above.
According to yet another aspect, an apparatus includes a mobile fluid storage device separate from a deposit device and generally movable over an array of deposit locations, the fluid storage device being constructed and arranged to resupply the deposit device at various locations with respect to the array, in one case, preferably the mobile fluid storage device being constructed to store a multiplicity of isolated fluid volumes, the apparatus constructed to move the mobile storage device relative to the deposit device to select the fluid to be deposited, preferably the deposit device being a pin or pin-like structure constructed and arranged, under computer control, to dip into a cleaning station periodically and in operation, dip into a selected volume of fluid carried by the mobile fluid storage device, preferably the mobile fluid storage device being a multiwell plate having 96 wells or multiples of 96 wells, or a spacing of 9 mm or a submultiple of 9 mm and preferably the apparatus including a driven stage for moving the fluid storage device into registry with the deposit device under computer control for enabling dipping of the deposit device into a preselected fluid volume; in another case preferably the mobile storage device is an annular ring that retains a supply of fluid by surface tension.
The present invention also features the method of use of all the described apparatuses. In the various methods, preferably the receiving surface is fragile, or soft, preferably the receiving surface is porous or microporous or fibrous, preferably comprising nitrocellulose, nylon cellulose acetate or poly nylidine fluoride or a gel, preferably the member defining the soft or fragile receiving surface being mounted on a rigid carrier member, either directly or upon an intermediate soft or resilient buffer member.
Preferably the method is employed to deposit a fluid selected from the group of biological fluids described in the specification, preferably the material being a biological probe or a chemical for reaction with biological material, a fluorescing material, an ink, dye, stain or marker, a photoactive material, or a varnish or an encapsulant or an etchant, or a cleaning or neutralizing agent.
According to yet another-aspect, the method of depositing a biological fluid with a pin (or a pin-like structure) comprising supporting fluid within a ring (or a ring-like structure) by surface tension, and moving the pin (or pin-like structure) through the ring (or the ring-like structure) in the manner that a relatively small drop of the fluid is held at the end of the pin (or the pin-like structure) by surface tension and deposited on a receiving surface, and moving the structures to a cleaning station.